HDR Images and Windows

What you see in person facing a window is often a well-balanced scene with a high dynamic range, something like the right side of this HDR image. (It is perhaps artistically embellished a smidgen, but not so much as to make it unrecognizable.)

Or, to put it another way, if you were standing inside, looking out the window, the room would look normally lit. The outside would also look normal.

During a nice, brightly lit day, however, if you take your camera and go to a room where you work or live that has a window in it, without using a flash or any other exposure aids, and try to take a photograph, you will get something more like the left side of the image.

Try it — take a photograph where the inside and the outside are both properly exposed. Turn the inside lights off and on to see whether it makes a difference. Put the camera in Auto mode or use different metering and exposure strategies if you like.

You’re not going to have much success, especially if you don’t use some serious interior lighting to balance the brightness of the interior with the outside. The problem is again dynamic range, pure and simple. Today’s digital cameras can’t capture a dim interior and a bright exterior without messing something up.

In this case, both areas suffer. As you can see on the left side of the image, the outside is blown out with details barely visible. The inside is completely dark. You would think the photographer was standing in a dark room photographing the surface of the sun through the revolving door! Nothing could be further from the truth.

With this example you can see that

Cameras struggle with inside-out shots. The dynamic range in this example, from a darker but well-lit interior to a very bright exterior, is huge. It’s impossible to capture the entire range of this scene in one digital photograph.

Reality is not always well represented. Traditional photographs aren’t necessarily a good indicator of reality, despite what some people will tell you. If you doubt that, find a location like this and compare what you see with your eyes to a photograph.